The Letter of Last Resort
by Pericula Ludus
Summary: Imagine the scenario. Britain has been wiped out by a surprise nuclear attack. The prime minister has been killed. Should Britain's nuclear submarine fleet launch its own missiles in retaliation? On a submarine somewhere on the bottom of the ocean, Captain Tréville and Athos have to make that decision. Their only guide is a handwritten letter from the PM—the letter of last resort.


_Imagine the scenario. Britain has been wiped out by a surprise nuclear attack. The prime minister has been killed. Should Britain's nuclear submarine fleet launch its own missiles in retaliation?_

 _It's a decision that will hopefully never have to be made. But one of the first things Theresa May had to do when she became prime minister was to write her "letters of last resort". The letters are one of the most secretive parts of the UK's nuclear programme, called_ _Trident_ _._

 _The UK has four submarines capable of carrying Trident nuclear missiles. Since 1969, one of those subs has always been on patrol, gliding silently through the world's oceans._

 _Every prime minister has to write four letters - one for each submarine. They are addressed to the Royal Navy commander on board. They are usually handwritten. The letters are locked in a safe aboard the submarine and destroyed, unopened, every time a new prime minister comes into office._

 _It's not known exactly what they say._

 _(BBC Newsbeat, 18 July 2016)_

* * *

 **Letter of Last Resort**

"Sit."

Tréville emphasized the word with a determined gesture.

Athos perched awkwardly on the edge of the captain's bed as Tréville himself occupied the only chair in the tiny cabin. Everything was cramped on board of a submarine, even the commander's cabin. They were able to create their own water, their own oxygen, but space; space was still at a premium.

But now...

This was the only space now; the only space that was left was this metal tube on the bottom of the ocean. Their location was known only to a handful of officers, but their mission—their mission was known to the world.

The Trident nuclear deterrent.

A _failed_ nuclear deterrent.

They had failed in their role, they hadn't deterred this devastating first strike, they had failed and millions had paid the price and now —

"Athos," Tréville interrupted his spiralling thoughts.

Athos swallowed heavily.

"Captain."

"Opening the letter..." Tréville nodded towards the envelope on his barely laptop-sized desk. "Are we certain?"

Athos stared at the letter as if it was going to answer on its own. With an effort he dragged his eyes up and reported to his commanding officer.

"We have executed the relevant protocols, conducted the validation procedures."

They had known before they had started. They had known when Tréville had sent the men away, keeping only two other officers inside the control room, the bare minimum, the Logistics Officer to pilot the submarine, and the Warfare Communications Officer to aid them in carrying out the various protocols.

"We are no longer receiving communication from any identifiable British source?"

"None."

"UK defence frequencies?"

"Silence."

"UK government?"

"Silence."

"Her Majesty?"

"Silence."

Silence.

So much silence that Athos had been able to hear his own heartbeat as he stood behind Porthos, watching him carry out Tréville's commands, meticulously working their way through the protocols designed to confirm the extent of the situation.

Each protocol had been passed.

Nothing but silence.

Tréville kneaded his forehead. He looked tired.

"No communication from military or civilian sources, no government or royal statement," Athos summarised. "And international sources indicate—"

"Not even Radio 4?"

"Not even Radio 4."

"That beacon of civilisation."

"If there were any way, _somebody_ at the BBC would be broadcasting."

"No Archers, no Gardener's Question Time, no Women's Hour."

"No Ambridge, no gardeners... no women."

The magnitude of Athos' statement hung in the air between them. For the first time in his career, Athos found it difficult to breathe inside the submarine. The weight of the ocean, of the world or what was left of it seemed to be pressing down on them.

"Two women," Tréville corrected and there was a hint of a smile on his face. "153 men and two women, that's all that is left of Britain."

It was a recent development, the first female submariners in the 110-year history of the Silent Service. Two of them were on board. Anne and Constance, the only British women left on this earth.

"There might be... the Falklands, some reports suggest that Orkney and Shetland... and there are those in foreign countries..."

"The last remnants of the Empire, penguin counters, islands who barely want to belong to Scotland much less the UK, sun-burned pensioners on the Costa Brava and a bunch of Ibiza stag parties."

Despite the seriousness of the situation, Athos huffed out a grim laugh.

"Not an entirely inaccurate representation."

They sat in silence as the brief burst of humour evaporated.

"We have every reason to believe that Britain as we know it no longer exists," Tréville said. "News broadcasts, foreign intelligence... we must assume that both London and Glasgow are obliterated. And with Glasgow, Faslane."

Her Majesty's Naval Base Clyde, Faslane, Scotland. Their base, their home when they couldn't be down here. The base for the other three Vanguard class nuclear submarines as well.

Gone.

"There are millions of deaths..." Tréville continued. "My condolences. Your family?"

Athos shook his head. "Deceased."

Then, realising how that sounded, he clarified "Long ago."

"A wife?"

Athos shook his head again.

"Girlfriend?"

 _No._

"Heavens, man, there must be somebody!"

"Everyone I care for is on the _Victorious_."

Tréville sighed deeply, covering his mouth with his hand.

"What about you, Sir?"

"My sister, nephews... friends, acquaintances..." He paused, shaking his head slowly. "Even my local's cantankerous landlady..."

"My condolences."

Millions.

Millions of lives turned to dust. It was too big, too incomprehensible. And down here, life went on. Steps on the corridor, a laugh somewhere in the distance.

"How are _you_ holding up, Athos?"

Athos stared at Tréville, not sure he had heard correctly.

"Sir? I hardly think that I... that it matters given the circumstances."

Tréville pointed at the letter.

"Once we open that, it's about the world. Once we open that door, it's about these men and women. Right now, it's about you and me. And personally, I'm terrified."

Athos blinked his eyes rapidly, taken aback.

"It's what we trained for," he replied stiffly.

Tréville smiled at him, a real smile, fond and fatherly.

"Training we hoped we would never need... that the world hoped we would never need. And we had good reason to believe we never would. No nuclear armed nation has ever attacked another nuclear armed nation."

"Until now."

"Until now..."

"I'm sorry, Sir." Seeing his captain raise a questioning eyebrow, Athos added. "It's your last tour. If I had been ready for command..."

"... I would be dead now," Tréville finished.

Athos flinched as if he'd been hit.

"I thank you for your consideration," Tréville added more gently. "I would not have it any other way. And I could not wish for a better second in command."

No better second in command.

A _wavering_ second in command.

Porthos' hand on Athos' shoulder, a reassuring squeeze the moment after the captain had nodded gravely and Athos had saluted in acknowledgement. One last friendly touch before they had approached secure stowage number 26, commander and second in command together, opening the safe that contained nothing but the letter.

The letter of last resort.

The letter that was now sitting on the captain's desk.

Athos breathed in deeply. That letter contained the weight of the whole world, its words holding promise or destruction.

"We should open it," he said, hoping he sounded more composed than he felt.

"We should," Tréville confirmed.

Neither one of them moved.

That letter... Athos had watched it arrive at Faslane the day after the new Prime Minister had accepted the Queen's invitation to form a government. He had watched Tréville lock it in secure stowage number 26. That letter was the sword of Damocles above their heads, the bane of their existence and the reason for it.

It didn't look too ominous, fairly innocent really. Heavy cream paper and on it, written in fancy blue ink, _Commander HMS Victorious._

Victorious.

No more.

Porthos' glance when they had left the control room... Porthos' eyes, sad, not frightened... concerned. For himself? For Athos? For the world? He was right to be concerned.

One submarine, eight ballistic missiles, each nuclear warhead five times as powerful as the one that devastated Hiroshima. The power to reshape the world. The order to wield it, in that letter.

"Poor woman," Tréville said, turning the letter in his hands. "What a weight to carry, what a decision to make on her first day in office..."

"If she was... still alive," Athos said tentatively. "She would have found a way to contact us..."

"She would have," Tréville confirmed. "God rest her soul. But we have her words, our very last orders."

"I guess we already know," Athos said. "She was rather decisive in her statements on Trident."

Tréville's fingers stopped moving and he looked directly at Athos.

"The only way a nuclear deterrent works. It's got to be believable."

" _They_ didn't believe it."

"Or they decided it was a risk worth taking... by the time we fire — _if_ we fire— the ones responsible are likely to have retired to a remote bunker."

"Leaving us to kill civilians." Athos let a breath out through his teeth. "Their capital for ours, their country for ours. Our revenge... a war crime. We'd be captured and tried as soon as we surfaced."

"We'd be following orders," Tréville said.

"That defense was invalidated at Nuremberg," Athos replied grimly.

"The last orders of a democratic UK government. The last remnant of democracy. You would refuse them?"

Athos buried his head in his hands. Worth it. The right thing to do. The only reason they were still here was to carry out those orders. Who was he to question them for his personal comfort and peace of mind?

"What about the crew?" he asked.

"I'd hope they would not be held responsible for a launch the two of us have carried out."

The two of them.

No one man was in charge of a nuclear weapons launch. The two of them, every step of the way—until that final simultaneous turn of the launch keys.

Athos tore at his hair, wanting to feel something other than the dread.

"They'd still have their conscience to answer to."

Tréville reached out, touching Athos' wrist very gently.

"Don't, Athos," he said. "Their families are dead, their lives in ashes. Whether we retaliate or not, this will be difficult for everyone on board. No need to make it worse."

"They don't even know yet."

"We will tell them in due course."

In _due course_? To hear from some officer that you had nothing left? He was the lucky one here; his life had been destroyed long ago.

Lucky.

The rest of them... Athos had no idea how Tréville could remain so calm... He realised he knew so little about the captain. Tréville was always there, always reliable, even now, even when he was —by his own admission— terrified.

Athos breathed deeply.

He _could_ breathe. There _was_ air; there was no weight pressing down on him. He was on board the _Victorious;_ undetectable, completely invisible even to the others that lurked in the deep.

He _was_ safe. Even if all the world went to hell, they were safe down here.

"We should open it," he said, forcing his voice to be steadier than he felt. "See what we are dealing with."

"Not too many options," Tréville said, staring at the letter in his hands.

"Retaliate... do not retaliate..."

"She could leave it at our own discretion. Or she could order us to put the _Victorious_ at the disposal of New Zealand, Australia... somebody."

"If we initiate communications we'd give away our location... we'd be sunk," Athos said, squirming in his seat.

"We have to surface eventually."

All this technology, all this power at their disposal and it came down to the one thing they couldn't produce on board—food. Surface or starve.

They could not hide forever.

"They all know we are out here," Athos said, trying to imagine the scenario above the surface. "They know what we can do."

"The world must be holding its breath," Tréville confirmed.

" _The Hunt for Red October_."

"We won't be showing _that_ movie tonight," Tréville said with a small smile. "But undoubtedly many are keen to locate us. Nothing new in that regard."

"Let's get it over with."

Athos squared his shoulders and made to get up, but Tréville held him back.

"Athos?"

"Captain?"

"Whatever this letter contains... whatever we do... You are still a good man and I want you to know that you have earned my highest respect."

Athos swallowed heavily. This felt too much like last words.

"Captain."

He stood behind Tréville as the captain slowly opened the envelope, careful not to tear it. He treated it as something precious, and Athos supposed it was. The last sign of British life beyond the confines of this submarine.

Athos held his breath as the folded sheet of paper emerged.

The letter wasn't long, a few lines of clear, accurate handwriting. A few lines that confirmed their fate and that of the world.

Athos read and reread the letter, each word burning itself into his mind.

Silence.

Eventually, Tréville turned in his seat.

"We have our orders," he said.

Athos drew himself up straight and saluted.

They weren't big on hierarchies and decorum in the Submarine Service. Three months in a metal tube without any escape or communications with the outside tended to blur the lines between officers and ratings. But this felt appropriate.

They had their orders.

The last orders they were ever likely to receive.

Their country, their queen, their government were all gone. They had the power to avenge them.

They had their orders.

Athos sat down heavily. It was all so surreal. Tréville's accurately made bed, the quiet sounds of operations beyond the door. The normalcy of it was so at odds with the turmoil in his head. In the control room, Constance and Porthos would be wondering, the only ones who knew for certain what was happening in the captain's cabin.

Aramis would have guessed.

He always did.

Once they opened that door, everyone would know.

"What do we do now?" Athos asked, trying to pull himself together.

Somehow he had only ever thought of this moment, of reading the letter. Never of the aftermath. Of course there had been drills; of course he knew exactly what to do, how to launch the missiles. Once they had a legitimate order, it was simple. A strict sequence of steps, a turn of the launch keys. Minutes later they would start to pick up evidence of their strike.

The process was clear.

They knew, they had always known. You didn't take this job without making your peace with it, without being ready to launch these weapons.

But now...

"We need to tell the men," Tréville said.

Silence.

"I'm not ready."

Athos surprised himself with that confession. He stared darkly at the door. Beyond it... his friends, his family, the people he loved. How would they react? Could they ever accept it? Their obliterated lives... his role in all of this...

"It's no longer between us," Athos said.

"The prime minister requests our discretion," Tréville said. "I will not order you, but it is her last wish."

"Of course."

Tréville carefully folded the letter, placed it back into its envelope and stored it in his pocket. He would keep this between the three of them for as long as he lived.

"She had no idea," Athos said.

Tréville nodded. "She would have been filled in on recent geopolitical developments, but nobody could have predicted... not back then." He sighed, stroking his beard. "The world was very different when she wrote this. 10 Downing Street, Westminster, London... those were more than memories to her."

They were more than memories to Athos. Places he had visited, a city he had lived in. The world always felt remote while they were on patrol. Not that much had changed.

Except for the silence.

Except for the fact that it was all history now.

Children would learn about this day at school. The first strike, the shock at a country wiped from the map, the time when the world held its breath, waiting for the actions of a submarine captain... _Their_ actions...

"It's not an order," Athos said.

Tréville nodded. "A thought, a suggestion, a reminder of what the world was like. She cannot enforce it, nor can anyone else."

Athos bit his lip.

"It was always going to be our decision."

Tréville closed his eyes. "I'm sorry, Athos."

No order, a suggestion. No certainty, just their decision.

"We have no authority."

"We have the _only_ authority."

Because everyone else was dead, every democratic structure destroyed, and somehow it was left to them, two men in a can, to take the fate of the world into their hands.

Millions were dead.

And Athos had no stake in this, had never cared enough to warrant one, had not truly lived beyond the service for so long... He was in no position to avenge them. He had no authority to decide _against_ revenge either.

"We have no more of an idea than she did."

And yet they were the men with their hands on the trigger.

"We know who did it. We know the damage they did. And we know how we feel about it."

Athos felt utterly inadequate.

There was no legitimation for what they were about to do. Knowingly killing millions. It was their job, if it came to it. Athos had not expected to find it that difficult to carry out.

He had hoped for certainty. The letter of last resort, a clear instruction for them to follow. He had always been told that there were only four options, as undoubtedly every prime minister had been told as well.

It had seemed simple.

Read one of those options; carry it out.

Live with what they had been ordered to do.

 _Simple._

The reality was much more complicated. The letter, as short and clear as expected, had brought more questions than answers.

"What has the world come to?" Tréville asked.

Athos looked up to see the captain sitting very upright, clutching the edge of the desk, his eyes staring into nothingness.

"It was not entirely unexpected," Athos said quietly. "Not this... but the factions, the terror... we knew..."

"Of course."

Tréville sounded dejected, for the first time since all this had started.

"We still have this," Athos said. "The submarine, us..."

"And what are we?"

A floating arsenal ready to destroy whatever was left of the world.

The ultimate suicide bombers.

The terror to end all terrors.

No.

"The _HMS Victorious,"_ Athos answered. "The remnant of one of the oldest armed forces, one of the oldest democracies in the world."

"So what are we first?" Tréville asked. "Military or democracy?"

Athos did not answer.

He was military.

He needed it like air.

The Submarine Service had given him a place and a purpose when everything had seemed lost. He had found friends and a format to fit into. It had shaped him, made him the one he was. They joked that the only woman in his life was the _Victorious._ The military came first, his devotion to his country, his lifestyle... the military trumped everything else, any semblance of a private life he might have had.

However...

"I have no stake in this," he said. He had been the military and not much else. "I have lost no loved ones up there. These men, these women..." The image of Anne's young son flashed in front of his eyes. "They have."

"Democracy then."

"Our crew are the last remnant of the sovereign."

"The military command structure was established for a reason," Tréville cautioned.

"We are not under fire," Athos countered. "We have weeks to make a decision."

"The responsibility..."

"We assume full responsibility for a launch," Athos said, surprising himself with his certainty. "The war crime would be ours, but the weight on their conscience... the men would carry it either way. They should have a say in the decision."

Tréville nodded, looking at him now, eyes alert once more. Athos had the impression that the captain saw more than his face, saw into the very depth of his soul.

It did not feel intimidating. On the contrary, it was comforting.

He had nothing to hide. He had just assumed responsibility for what would be the worst war crime in history. He knew he could. With Tréville by his side, he could face the International Criminal Court. They would go to The Hague and face their punishment, upright and in the belief that they had been worthy of the UK's legacy.

Athos sat up straighter. It was the right decision.

"The letter..." Tréville prompted.

"Ensures that until the very end, the legitimate, democratically elected finger remains on the trigger." Athos took a deep breath and released it slowly. "We are _not_ that finger, not like this."

"You are proposing a vote." Tréville finally voiced it. "Retaliate—do not retaliate."

"Yes."

"Unconventional."

"We have gone beyond convention."

Of course they had protocols for this. They had protocols for everything. But what protocol—written in the comfort of a world that still held the British Isles—could capture their reality?

Tréville smiled.

"Very well then, a vote," he said. "But no simple majority. We've had too many close referenda."

Athos smirked. "We do not want to be the 45."

" _Nobody_ should have to be the 45 in this," Tréville said seriously. "We have time to repeat the vote if necessary. Two thirds?"

"Like the pope."

"A tried and tested system. A supermajority is needed for changes to many constitutions. This feels even more serious than that."

Athos nodded and stared at his shoes. The full magnitude of his proposal was becoming apparent to him. He was putting the lives of millions in the hands of 155 submariners. Millions had already died today, millions more might follow soon. Millions of enemies, millions of innocent civilians. Athos wasn't sure what they actually were.

He continued to stare at his shoes, waiting for the surge of thoughts to subside. His shoes were spotless. His conscience—not so much.

"We have to tell the men," Athos said. They kept coming back to that. They had dithered long enough, had left those who trusted them hanging. Athos brushed a hand across his face, smoothing the lines on his forehead.

"Face to face," Tréville decided. "We do not want them to hear it over the intercom."

"How?" Athos asked. "They should hear it simultaneously."

Never enough space on a submarine. No space to hold them all.

"The masses. Officers, senior ratings, junior—we take one each."

Athos closed his eyes.

All eyes on him, waiting to hear the truth after the inevitable rumours. On a submarine, gossip spread faster than a fart in an elevator. Telling them that their families, their friends, their lives, and their country were no more. He could not even begin to imagine the pain his words would cause. But he would also be telling them that they were valued, that their pain was recognised and gave them a vote in the most serious decision of their lives. He'd be telling them that they were not powerless.

Athos opened his eyes.

He could do that.

"Porthos can take the third," he suggested. "He's popular with the junior ratings."

Admired would be a better word. Admired for having risen through the ranks but maintaining his common sense and never ignoring his roots. And Porthos was good with emotions... More than once he had brought the news of a death in the family to one of the men the day before they surfaced.

Not that it was the same thing.

This wasn't about a single grandmother, a father, or even a wife. Everybody was dead now. Constance's husband, d'Artagnan's parents, Aramis' ever-changing girlfriends, Anne's young son. Everyone.

"Very well," Tréville said and rose to his feet. "To the control room, then."

He held his right hand out to Athos, a gesture caught between helping him up and shaking his hand. Athos' legs were trembling when he stood and he took a deep breath to steady himself.

Tréville clasped Athos' hand between both of his. Athos looked at him, expecting a speech, some advice, a way to phrase what they would have to say. Instead, Tréville just nodded.

"Courage."

* * *

 ** _Endnotes & Briticisms_**

This is my first ever AU for anything... I don't even read many AUs, so this is really daunting... please be kind to this bumbling beginner.

This work was inspired by recent news coverage and by David Greig's brilliant play "Letter of Last Resort" which you can find on YouTube. Highly recommended listening for the other side of this letter writing process.

 _Trident —_ Trident is genuinely the UK nuclear deterrent and this is how it works. The letters are real and so are the submarines I have frequently seen while traipsing around Scotland. The introductory note is an actual article from the BBC. As you can imagine public information about the whole process is somewhat limited, so any gaps in what I could research are filled by my imagination.

 _Vanguard Class —_ 4 nuclear submarines (HMS Vanguard, Victorious, Vengeance, Vigilant) that are the sole base for the UK's nuclear weapons. The submarines do not need to refuel and produce their own water and air, so their range is only limited by food supplies. When on patrol they operate silently and while they receive transmissions they do not send any, making them virtually undetectable with current technology. It works reasonably well—HMS Vanguard once collided with a French nuclear submarine because they could not detect each other.

 _Radio 4 —_ The BBC's spoken-word radio station, very popular and filled with some great journalism and some real cultural icons. For example "The Archers" the world's longest-running radio soap opera which is set in the village of Ambridge (to any British readers now humming the theme tune again, you're welcome). Radio 4 is commonly believed to be part of the list of broadcasts the submarine commanders check to verify that the UK is no more.

 _Faslane —_ Some 35 miles outside of Glasgow on the Gare Loch in Scotland is where Her Majesty's Naval Base Clyde is located, the base for the four Vanguard class submarines. There is also a permanent protest camp against nuclear weapons.

 _The Sword of Damocles —_ Famous Greek moral tale about the imminent and ever-present peril faced by those in positions of power, depicted in the story by a sword hanging above Damocles' head held only by a single hair. With great power comes great responsibility...

 _Nuremberg —_ The Nuremberg trials or _Nürnberger Prozesse_ were a series of military tribunals held after World War 2, notably prosecuting Nazi leadership and establishing some principles about war crimes, which makes them relevant in this context, namely that following orders is not a valid defense, and even if an action is not illegal under national law, it can still constitute a war crime. Paraphrasing for brevity here.

 _The Hunt for Red October —_ Tom Clancy's 1984 novel about a rogue Soviet submarine during the Cold War, also a 1990 movie. Very good Cold War submarine movie fare, but I might be biased because Sean Connery is the protagonist.

 _One of the oldest democracies... —_ Like many of my characters, much of the time, Athos is wrong here. It's actually a difficult question and depends on how you define democracy... The Icelandic _Alþingi_ was established as a parliament in 930 and in the British Isles the Isle of Man's _Tynwald_ claims to date back to 979. The _Parliament of Great Britain_ was formed in 1707 following the ratification of the _Treaty of Union_ by _Acts of Union_ passed by the _Parliament of England_ and the _Parliament of Scotland_ that were both established in the 13th century. So there is definitely a long history of some sort of democracy. If you're looking for universal suffrage, New Zealand was first in 1893.

 _International Criminal Court —_ An international tribunal that sits in The Hague in the Netherlands. Has jurisdiction to prosecute individuals for the international crimes of genocide, crimes against humanity, and war crimes.

 _The 45_ _—_ "We are the 45%" emerged as a slogan after the Scottish Independence Referendum in 2014 in which 45% voted for independence.


End file.
